Notes: "Adolph Lietz was a German immigrant who came to San Francisco in 1879, at the age of 19, and worked in several scientific instrument shops before opening his own business at the age of 22. The company was incorporated under the name, “The A. Lietz Company” in 1892, and stuck with that name until 1965 when it was bought out and moved to Kansas City, Missouri. Lietz was a manufacturer of surveying and drawing instruments up to 1947, but after 1947 the company ceased all manufacturing and became an importer and distributor. Lietz sold slide rules from several different manufacturers, but especially Hemmi. This one is a Mannheim design. "